There´s no better way to kick off the year than with fresh ideas to expand our knowledge and improve our skills as exploration geoscientists. To help you out with that, we compiled in this special edition some exciting contributions from various researchers from all across Canada that cover some state-of-the-art techniques that aim to better understand the anomalies seen on various types of geophysical datasets. We hope this special edition to be as enjoyable for you to read as it was for us putting it together.
To begin this edition, Amanda Obodovsky discusses the implementation of state-of-the-art seismic processing techniques to better visualize impact craters (or “astroblemes”) on 2D and 3D seismic surveys ('Impact Craters in Seismic Data'). Impact craters can play a key role on oil and gas exploration as the rim structures can act as traps for conventional petroleum systems, as those developed in the Viewfield and Steen River fields in southern Saskatchewan and northern Alberta respectively. Amanda implements diffraction imaging and SPRINT 6D interpolation to reprocess a 3D seismic survey acquired in the central Alberta Foothills region in the late 1980’s, where a cryptoexplosion structure, interpreted as an impact crater, was first observed. Two more case studies from the Hotchkiss Impact Structure in NW Alberta, and the Manyberries Astrobleme in SE Alberta, are discussed by implementing the same processing techniques in the 2D seismic surveys acquired in these areas. The obtained enhancement of the seismic images is remarkable in all case studies, so it is the endless possibilities to implement the same techniques to keep exploring impact craters from existent seismic datasets from all around the world.
Later on, Le Gao and Igor Morozov describe the implementation of a new, azimuthally-uniform skeletonization approach to interpret 2D gravity and magnetic databases ('Skeletonization and Empirical-Mode Decomposition of 2-D Potential-field Images'). This technique, originally targeted for automatic event picking in reflection seismic data, requires the identification of elementary “anomalies”, or “wavelets” in gridded images, and a subsequent connection of these wavelets to form the “skeleton” of the image. In seismic sections, the skeleton can be interpreted as a set of “horizons”, and in the potential-field case, it comprises any “lineaments” (elementary linear and potentially branching features) detected in the image. Each of these “lineaments” is associated with a set of parameters referred to as the “feature set” and can be interconnected with other “lineaments”. This technique is implemented in combination with 2D Empirical Mode Decomposition (EMD) to interpret an aeromagnetic and a gravity database from part of the Williston Basin in southeastern Saskatchewan and southwestern Manitoba.
Finally, David Eaton and his colleagues from four research institutes from all across Canada, provide an introduction to the proposed Canadian Cordillera Array (CCArray) project designed upon previous Earth-systems research and data collection initiatives, such as Canada’s LITHOPROBE program (1984 – 2004) and the EarthScope program in the U.S. (2004 – 2019) ('CCArray and EON-ROSE: Emerging Pan-Canadian Multidisciplinary Research Initiatives'). This highly ambitious project consists on the installation of a network of broadband seismometers and Global Navigation Satellite System (GNSS) equipment that aims to understand the earth structure, tectonics, earthquake occurrence and seismic hazard, glacial isostatic adjustment, induced and triggered seismicity, and vertical land motion for robust relative sea-level projections in western Canada. Other proposed sensors for the same grid include relative and absolute gravimeters, and atmospheric, meteorological and magnetotelluric systems, together with the establishment of a network of new Critical Zone Observatories (CZOs). CCArray represents the first stage of the EON-ROSE initiative, that plans to expand the proposed monitoring network to all across the country.
About the Author(s)
Katie McLean joined our committee in January 2018. She recently graduated from the University of Alberta with a B.Sc. in Geophysics. At U of A, she was the Geophysics Representative to the Western Inter-University Geosciences Conference 2017; she was active in the Geophysics Undergrad Society, and she was on the Pandas Varsity Golf Team. Katie will be our Special Coordinator for the January 2019 edition, which will present research from universities across Canada and launch our series, Geoscience Across Canada. She will also be key in helping the RECORDER evolve into a truly digital magazine.
Germán Rodríguez-Pradilla is a Research Assistant at the Microseismic Industry Consortium, and a Ph.D. candidate in Geophysics at the University of Calgary. He holds a B.Eng. in Civil Engineering and a M.Sc. in Geophysics from the National University of Colombia, and his current research focuses on developing robust methods and algorithms for microseismic data processing and modeling applied to unconventional reservoir characterization and hazard analysis of induced seismicity sequences. He has presented his research work in multiple international conferences and journals, and has also served as a technical editor for CSEG RECORDER since 2018.